Embolic agents are useful for a variety of bioapplications, such as occluding blood vessels, occluding aneurysms, occluding other body lumens such as fallopian tubes, filling aneurysm sacs, as arterial sealants, and as puncture sealants.
Embolization of blood vessels is performed for a number of reasons, e.g. to reduce blood flow to and encourage atrophy of tumors, such as in the liver, to reduce blood flow and induce atrophy of uterine fibroids, for treatment of vascular malformations, such as arteriovenous malformations (AVMs) and arteriovenous fistulas (AVFs), to seal endoleaks into aneurysm sacs, to stop uncontrolled bleeding, or to slow bleeding prior to surgery. An aneurysm (a dilation of a blood vessel) poses a risk to health from the potential for rupture, clotting, or dissecting. Rupture of an aneurysm in the brain causes stroke, and rupture of an aneurysm in the abdomen causes shock.
Gynecologic embolotherapy may be conducted for a variety of purposes including the treatment of uterine fibroids, the treatment of postpartum and post caesarean bleeding, the treatment of post surgical vaginal bleeding, the prevention and/or treatment of hemorrhage from ectopic pregnancy, prophylactically prior to myomectomy and in obstetrical patients at high risk for bleeding, such as those patients with placenta previa, placenta accreta, uterine fibroids, and twin fetal death.
Embolics have also been used to treat cancer. For example, embolics can be used to occlude the vasculature feeding a solid tumor. As an adjunct to embolization, drug-loaded embolics, such as drug-loaded microspheres, have been used for in situ delivery of chemotherapeutic agents and/or therapeutic agents designed to treat inflamed or diseased tissue. In addition, clinicians have administered chemotherapeutic agents in combination with embolic PVA particles. This type of regional therapy may localize treatment at the site of the tumor, and therefore the therapeutic dose may be smaller than the effective systemic dose, reducing potential side effects and damage to healthy tissue.
Liquid embolics as well as polymer-based particles and embolic microspheres currently used for indications described above are known. See, e.g., U.S. Pat. Nos. 7,311,861 and 6,676,971 and references cited therein, incorporated by reference in their entireties herein. These embolics are usually introduced to the site of desired embolization via microcatheters.
However, embolics are currently sold in prepackaged form, for example as a vial or syringe containing a set quantity of embolic and/or drug. See, e.g., Onyx® Liquid Embolic System, sold by the Endovascular Company. As a result, the health care professional administering the embolic cannot use an amount of embolic and optional drug other than what is supplied in the container. Moreover, for embolics packaged with additional therapeutic compounds, the physician cannot alter the ratio of embolic to drug for individual patients. Changing the amount of embolic and/or the ratio of therapeutic agent to embolic requires the physician to spend extra time carefully removing the embolic from its packaging, weighing of measuring the desired amount of embolic, mixing the desired amount of embolic with a set amount of the therapeutic drug and then charging the drug-loaded embolic back into the delivery device.
Thus, there remains need for embolic formulations that allow for the health care professional to readily deliver any selected amount of embolic and/or therapeutic agent.